Machshirin 2:11

[What you need to know: In the seven-year cycle, produce of years 1, 2, 4 and 5 is subject to second tithe; produce of years 3 and 6 is tithed for the needy. Year 7 is the Sabbatical year. This mishna discusses when produce from two years is mixed together.]

If there was more year 2 produce than year 3 produce, more from year 3 than from year 4, more from year 4 than from year 5, more from year 5 than from year 6, more from year 6 than from year 7, or more from year 7 than from the year that follows it, we proceed according to whichever is greater. If they’re 50/50, we act stringently.

Machshirin 3:1

Let’s say that one placed a sack of produce on a river bank, on top of a well or on the steps of a cave and it absorbed moisture. The moisture absorbed is subject to ki yutan. Rabbi Yehuda says that ki yutan applies to anything that is placed adjacent to water; ki yutan doesn’t apply to things that weren’t placed adjacent to water.